Gas purification



H. F. SMITH.

GAS PURIFICATION. APPLICATION FILED AUG.4, 1911. RENEWED AUG. 4, 1920.

Patented Nov. 9, 1920.

IIIf/drlrlll m I HUM-125 5 'wtalf, 131 LEXINGTQN, (331 .12),

ENG" CQFliPl-LJY, i

1 4 il oho oo o ti t.

Specification of Letters Patent.

Application filed August 4, ISlL'Serial No. 184,452. Renewed August 1-, 1920. rial Ho. 491,2"?9.

To all whom it may concern:

Be it known that l, HARRY F. Smrrrn a citizen or the United States of America residing Lexington, Richland county Ohio, have invented certain new and useful linprovenients in Gas Purificatioin of which the following is a full, clear, and exact description.

This invention relates to gas purification, and more particularly to the use of electrical means for securing the removal of vapors and like impurities from gases, such; for instance, the tar vapor which is found in producer gas. The object of the invention to provide an effective apparatus making use of electrical energy for removing such impurities from gas, which is sutiiciently simple and easy of operation to permit of its practical use. The apparatus forming the subject of this invention is especially designed for carrying into practice the method of gas purification, described in my co-peuding application, bearing Serial Nina ber 18 1 456 and filed Aug. 4, 1917.

The method described in the above referred to application consists broadly in subjecting the impurity containing gas to a brush discharge to produce prolific ionization of such impurities, and then passing the gas with its electrified particles, through a direct current field of sufiicient intensity to cause the migration of those particles to the electrodes, with a consequent precipitation of the particles upon the electrodes. In this invention. precisely the same method is carried out, but the apparatus described herein for carrying out that method differs in certain essential features from the apparatus described in the above referred to application.

The apparatus forming the subject matter of this invention is fully illustrated in the drawing, herewith, in which 1 is a treating chamber having an inlet 2 in one end and an outlet 3 in the other end thereof. The bottom or outlet end of this treating chamber is open and extends into a tanl: e1 containing any desired liquid water being' found very desirable when producer gas is being purified, which acts as a seal therefor.

Extending through the sides of the treating chamber, near the upper or inlet end thereof, are two electrodes 5 and 6, which are insulated in any desired manner from the walls through. which they pass, the insulation being shown conventionally at 11. Each of these electrodes is connected, by suitable connecting means, with one end secondary coil of a transformer 7 the connections being such that any current passing through the transformer 7 will inipress charges of opposite polarity upon these two electrodes. ()onnected to the primary coil of the transformer 7 is a source of alternating current 8. This arrangement is obviously such that any alternating current generated at 8 will induce in the secondary coil of the transformer 7 a corresponding alternating potential of the same frequency, but of a considerably higher potential, the potential depending upon the ratiobetwe'er. the primary and secondary coils of the transformer. The coils of the transformer T are so proportioned that the difference oi potential between the electrodes 5 and 6 will be sufficient to readily cause a brush discharge therebetween.

coated in that part of the treating chamber adjacent the outlet 8 is a series of plates 9, which plates are connected to any desired source 10 of direct current, the connections between these platesand the source of direct current being insulated in any suitable manner from the walls of the treating chan1- her: through which they pass the insulation being shown conventionally 12. The electrodes 9 must also be insulated from the treating chamber 1, and such insulation may be of any preferred form. The direct current generated by the source 10 should not be of SUfllClQil't intensity to produce sparking between the electrodes 9, even though these electrodes be placed quite close together but should be of sulticient intensity to produce pronounced electrical field therebetween. and of sufiicient intensity to cause a migration to the electrodes thereof of any ions or electrified particles of impurity passing therebetwcen. it is to be understood that my invention is not limited to the use of a direct current precipitating field as, although ll prefer such a field, a unidirectional current field would function about as well.-

In operating the above described purity ing apparatus, the impure gas passed into the treating chamber through the inlet 2. it the same time an a; rnating current is generated at 8, which passes through the primary coil of the transformer 2' and induces in the secondary coil thereoi an alternating current of very high potential. This high potential impresses on the electrodes 5 and 6 a correspondingly high potential of opposite polarity, the alternating character of the current insuring, of course, an extremely rapid reversal of polarity on each electrode. The diiierence of potential between the electrodes 5 and 6 should be suiiicient to cause a brush discharge therebetween, the potential necessary for causing such discharge depending upon the distance between these two electrodes. These elecodes are so placed that gas introduced anrough the'in'let 2 will be subjected to the brush discharge therebetween, the eiitect of such brush discharges being to ionize the impurities, contained in the gas; in other words, impress on such impurities an electrieal charge, which electricalcharges will be in part positive and in part negative be cause of the alternating character of the dis charge. The gas containing these electrified particles then passes through the direct current field surrounding the electrodes 9. At such time the charged particles in the gas acting under the influence of this direct can rent field will move toward and contact with the electrodes where they will be retained. The impurities it liquid will run down into the tank i from which they may be easily withdrawn. Ti not liquid, they-will still be precipitated upon the electrodes 9 and, because of the low potential existent upon such electrodes, may be readily withdrawn there from in any desired manner. The gas, thus relieved of its impurities, then passes out of the treating chamber through the outlet 3, and is led to any desired point of use or storage.

The apparatus described above lends itselt to a satisfactory and safe cleaning of impurity bearing gases. The high potential electrodes used are of small size, when com pared to the high potential electrodes used in the usual types of electric precipitators now on themarket, and in addition they are not adapted to act as precipitators. As a consequence it is much easier to maintain these electrodes properlyi insulated. And, too, because they are not used as precipitating electrodes, the danger attendant upon operation of the device is considerably decreased. Further the precipitating electrodes, because of the low potential field surrounding them may be readily maintained properly insulated, and in addition because ot the low potential existing thereon cleaning of the electrodes is a comparatively simple and safe matter.

It is easily possible to substitute for the source of alternating current of high potential used herein, either a unidirectional alternating 'current or a direct current-of high potential; but, it either of these types of current is used, care must be taken to so time the exposure of the impurity containing gas to the brush discharge produced t ereby that no deposition of impurities will talre place uponthe electrodes. With an alternating current as the source oi high potential it is very easy to avoid any such deposition. since the reversals or" direction of flow are su'hiciently rapid to prevent any substantial translation of the particles of impurities toward the electrodes,

l rom the above, it is thought evident that have invented an apparatus tor eliminatties from gases, which is extremely construction and operation, and decided improvement over any form of electrical purifying apparatus heretofore know This a la atus is especially designed for gas, but i s quite evident that its applicability "by no means limited to the removal of tar alone, and that can be utilized as readily in removing from gases any contained impurities, regardless oi their character.

llhat 1 claim as new and desire to secure by Letters Patent 1S--- 1. ln a gas purifying apparatus, the combination with a treating chamber having an inlet and an outlet, of an electrode therein intermediate the inlet and outlet; means connected to said electrode and adapted to cause an electrical discharge within the treating chamber adjacent said electrode;

a second electrode within said chamber and intermediate the first-named electrode and the outlet; and means connected to said second electrode, adapted to set up an electrostatic field or constant polarity Within the treating chamber.

2. in a gas purifying apparatus, the combination with a treating chamber having an inlet and an outlet; of a plurality of electrodes therein intermediate the inlet and the outlet; means connected to said electrode for causing an ionizing discharge therebetween; a plurality of other electrodes within the treating chamber and intermediate the firstnamed electrodes and, the outlet of said chamber; and means connected to said lastinamed electrodes and adapted to set up a low potential precipitatingfield within said treating chamber.

3. An electrical purifying apparatus comprising a treating chamber having an inlet and an outlet therein, means for producing a brush discharge therein adjacent the inlet, and means for producing an electrostatic field of constant polarity therein adjacent the outlet.

t. lln an electrical gas purifying apparatus, a treating chamber having an inletnnd an outlet in opposite ends thereof, means connected with the inlet end thereof and inst tar particles from producer r till ltd

cluding a source of alternating current for means connected to said second electrodes producing an ionizing brush discharge, and adapted to set up an electrostatic field of means connected with the outlet end and inconstant polarity within the chamber.

eluding a source of unidirectional potential 6. An electrical purifying apparatus com- 5 for producing an electrostatic field capable prising a treating chamber having an inlet 25 of causing precipitation of electrified parand an outlet; an electrode therein interticles passing therethrough. mediate the inlet and outlet; means con- In a gas purifying apparatus, the comnected to said electrode and adapted to cause bination with a treating chamber having an an ionizing discharge within the chamber 10 inlet and an outlet, of a plurality of elecand adjacent thereto; a second electrode 30 trodes within said chamber" and intermediwithin the treating chamber and intermeate the inlet and outlet thereof; a source-of diate the first named electrode and the outelectrical potential connected to said elec-' let, said electrode being separate from the trodes and adapted during operation to cause first named electrode; and a source of elec- 15 a flow of electricity from said source of potrical potential associated with said last 36 tential between said electrodes, said flow of named electrode, for setting up a low poelectricity' being in the nature of an ionizing tential electrical field adjacent said elecdischarge; a plurality of electrodes within trode. the treating chamber and intermediate the In testimony whereof I aflix my si nature.

20 first named electrodes and the outlet; and HARRY F. S ITH. 

